The Snowy Owl

One of the most iconic and revered birds of the Northern Hemisphere, Snowy Owl, has got a monograph successor following Leonid Portenko’s Die Schnee-Eule (1972). Eugene Potapov and Richard Sale have now presented the current knowledge and scientific achievements of those trying to unravel the species’ biology.

Probably the most important feature of the new book is the effort to summarise this knowledge into an analysis of how Snowy Owl is distributed throughout the Arctic. The authors’ interpretation of the species’ breeding system as made up of 5 to 10 “loose boids” (a boid being a unit of peer-influenced group movement rather than a sub-population) results in an estimate of the total world population fluctuating between 5,000 and 14,000 pairs only. The latter figure is less than 10 per cent of the number currently cited by the IUCN of about 300,000 birds, and confirms results published in 2009 based on DNA studies of Snowy Owls from the Holarctic. These two different approaches should raise awareness and ultimately concern for the future of Snowy Owl, and place it on the international Red List of birds.

The book includes detailed information on Potapov’s studies on ecosystems and Snowy Owls on the Russian tundra. The analysis on how population and body sizes of lemmings and voles influence breeding, clutch size and chick survival of Snowy Owls provides a new and intriguing understanding of the conditions necessary for the species to breed. Unfortunately, however, much current knowledge and data from other parts of the species’ range is not included.

The authors outline new telemetry study results from around the Arctic, data which really underlines that the future management and protection of Snowy Owls is a matter of international co-operation.

The photo section could have been improved with a more diverse selection of images showing different aspects of the species’ biology. There are many photos that depict the same situations and behaviour. Most birders who see a Snowy Owl would have benefitted greatly from a wider variety of photos illustrating plumages of different sex and age classes.

There are flaws concerning the cited literature, with important works missing from the list. It is also regrettable that correctional information did not make it into the final print, although this may have more to do with the publisher than the authors. The distribution maps also have issues, classifying both glaciers and inhabitable areas as breeding ranges, and depicting breeding areas with the wrong colour codes.

A second print of the book would benefit from a thorough revision. However, in spite of the flaws, this monograph is well worth reading for anyone interested in one of the world’s most spectacular owls.